Enhancing Selectivity and Kinetics in Oxidative Photocyclization by Supramolecular Control
Haldar, R. / Diring, S. / Samanta, P.K. / Muth, M. / Clancy, W. / Mazel, A. / Schlabach, S. / Kirschhöfer, F. / Brenner‐Weiß, G. / Pati, S.K. / Odobel, F. / Wöll, C. (2018)
Angewandte Chemie International Edition, 57, 41, 2018, 13662-13665
- Datum: August 2018
Photochemical reactions typically proceed via multiple reaction pathways, yielding a variety of isomers and products. Enhancing the selectivity is challenging. Now, the potential of supramolecular control for oxidative photocyclization of a tetraarylethylene, containing a stereogenic −C=C− bond, is demonstrated. In solution, this photochemical reaction produces three constitutional isomers (substituted phenanthrenes), with slow kinetics. When the reactant is assembled into a crystalline framework, only one product forms with accelerated kinetics. Key to this selectivity enhancement is the integration into a surface grown metal–organic framework (SURMOF); the dramatic gain in selectivity is ascribed to the hindrance of the rotational freedom of the −C=C− double bond. The structure of the MOF is key; the corresponding reaction in the solid does not result in such a high increase in selectivity. A striking change of luminescence properties after photocyclization is observed.